Calculating Coagulation Factor Levels Following the Transfusion of FFP.
john puetz, Saint Louis University
2 May 2014
In the manuscript "Plasma in the PICU: why and when we should transfuse?" Labarinas et.al. calculate how to provide 30% of additional coagulation factor using FFP.1 However, they failed to take into account that the transfusion of 12 ml/kg will increase the patient's circulating plasma volume from 40 ml/kg to 52 ml/kg. This will only raise the coagulation factor level by 24% and not 30% as indicated in the manuscript. This assumes that all of the infused factor remains in the circulation, which is the case for factor VIII, but not factor IX. Following the infusion of 12 ml/kg of plasma, the factor IX level is calculated to increase by only 12%. A clinical study comparing coagulation factor levels following infusion of 12 ml/kg versus 33 ml/kg of FFP by Chowdhury et. al. shows that infusion of 30 ml/kg is necessary if one wishes to target an increas of a coagulation factor by 30%.2
1. Labarinas S et al. Plasma in the PICU: why and when shoud we transfuse? Annals of Intensive Care 2013; 3: 16
2. Chowdhury P et. al. Efficacy of standard dose and 30 ml.kg fresh frozen plasma in correcting laboratory parameters of haemostasis in critically ill patients. Br J Haematol 2004; 125: 69-73
In the manuscript "Plasma in the PICU: why and when we should transfuse?" Labarinas et.al. calculate how to provide 30% of additional coagulation factor using FFP.1 However, they failed to take into account that the transfusion of 12 ml/kg will increase the patient's circulating plasma volume from 40 ml/kg to 52 ml/kg. This will only raise the coagulation factor level by 24% and not 30% as indicated in the manuscript. This assumes that all of the infused factor remains in the circulation, which is the case for factor VIII, but not factor IX. Following the infusion of 12 ml/kg of plasma, the factor IX level is calculated to increase by only 12%. A clinical study comparing coagulation factor levels following infusion of 12 ml/kg versus 33 ml/kg of FFP by Chowdhury et. al. shows that infusion of 30 ml/kg is necessary if one wishes to target an increas of a coagulation factor by 30%.2
1. Labarinas S et al. Plasma in the PICU: why and when shoud we transfuse?Annals of Intensive Care 2013; 3: 16
2. Chowdhury P et. al. Efficacy of standard dose and 30 ml.kg fresh frozen plasma in correcting laboratory parameters of haemostasis in critically ill patients. Br J Haematol 2004; 125: 69-73
John Puetz MD
The appropriate dose of plasma transfusion is still debated. As stated by Puetz, some mathematical models seem to indicate that higher doses are needed to correct low coagulation factors. In the study cited by Puetz, individual coagulation factors were indeed increased by higher transfusion doses. However, the PT values were similar in both groups. Other studies have also assessed the effect of the plasma dose on coagulation tests. It has been shown that even higher doses could not correct mildly abnormal coagulation tests [Abdel-Wahab, Transfusion 2008]. Furthermore, Tinmouth et al published in 2008 a study in which they randomized 12 ml/kg vs. 20 ml/kg, in 40 critically ill patients needing plasma transfusions [Tinmouth et al, Transfusion 2008, vol 48 (S1), S69-030E]. The authors concluded that "there were no differences observed in the effectiveness of standard and high dose FP transfusions to reduce the INR < 1.5 or increase the individual coagulation factors above a minimum hemostatic threshold.»
Furthermore, it has also been shown that abnormal coagulation tests do not correlate with an increased risk of bleeding [Segal et al, Transfusion 2005]. Therefore, measure of individual coagulation factors or regular coagulation tests do not seem helpful to assess the efficacy of plasma transfusion.
In conclusion, the appropriate dose has still to be defined, based on a clinically meaningful transfusion trigger.
Calculating Coagulation Factor Levels Following the Transfusion of FFP.
2 May 2014
In the manuscript "Plasma in the PICU: why and when we should transfuse?" Labarinas et.al. calculate how to provide 30% of additional coagulation factor using FFP.1 However, they failed to take into account that the transfusion of 12 ml/kg will increase the patient's circulating plasma volume from 40 ml/kg to 52 ml/kg. This will only raise the coagulation factor level by 24% and not 30% as indicated in the manuscript. This assumes that all of the infused factor remains in the circulation, which is the case for factor VIII, but not factor IX. Following the infusion of 12 ml/kg of plasma, the factor IX level is calculated to increase by only 12%. A clinical study comparing coagulation factor levels following infusion of 12 ml/kg versus 33 ml/kg of FFP by Chowdhury et. al. shows that infusion of 30 ml/kg is necessary if one wishes to target an increas of a coagulation factor by 30%.2
1. Labarinas S et al. Plasma in the PICU: why and when shoud we transfuse? Annals of Intensive Care 2013; 3: 16
2. Chowdhury P et. al. Efficacy of standard dose and 30 ml.kg fresh frozen plasma in correcting laboratory parameters of haemostasis in critically ill patients. Br J Haematol 2004; 125: 69-73
John Puetz MD
Competing interests
I have no competing interestAppropriate dose of plasma transfusion
24 May 2014
In the manuscript "Plasma in the PICU: why and when we should transfuse?" Labarinas et.al. calculate how to provide 30% of additional coagulation factor using FFP.1 However, they failed to take into account that the transfusion of 12 ml/kg will increase the patient's circulating plasma volume from 40 ml/kg to 52 ml/kg. This will only raise the coagulation factor level by 24% and not 30% as indicated in the manuscript. This assumes that all of the infused factor remains in the circulation, which is the case for factor VIII, but not factor IX. Following the infusion of 12 ml/kg of plasma, the factor IX level is calculated to increase by only 12%. A clinical study comparing coagulation factor levels following infusion of 12 ml/kg versus 33 ml/kg of FFP by Chowdhury et. al. shows that infusion of 30 ml/kg is necessary if one wishes to target an increas of a coagulation factor by 30%.2
1. Labarinas S et al. Plasma in the PICU: why and when shoud we transfuse?Annals of Intensive Care 2013; 3: 16
2. Chowdhury P et. al. Efficacy of standard dose and 30 ml.kg fresh frozen plasma in correcting laboratory parameters of haemostasis in critically ill patients. Br J Haematol 2004; 125: 69-73
John Puetz MD
The appropriate dose of plasma transfusion is still debated. As stated by Puetz, some mathematical models seem to indicate that higher doses are needed to correct low coagulation factors. In the study cited by Puetz, individual coagulation factors were indeed increased by higher transfusion doses. However, the PT values were similar in both groups. Other studies have also assessed the effect of the plasma dose on coagulation tests. It has been shown that even higher doses could not correct mildly abnormal coagulation tests [Abdel-Wahab, Transfusion 2008]. Furthermore, Tinmouth et al published in 2008 a study in which they randomized 12 ml/kg vs. 20 ml/kg, in 40 critically ill patients needing plasma transfusions [Tinmouth et al, Transfusion 2008, vol 48 (S1), S69-030E]. The authors concluded that "there were no differences observed in the effectiveness of standard and high dose FP transfusions to reduce the INR < 1.5 or increase the individual coagulation factors above a minimum hemostatic threshold.»
Furthermore, it has also been shown that abnormal coagulation tests do not correlate with an increased risk of bleeding [Segal et al, Transfusion 2005]. Therefore, measure of individual coagulation factors or regular coagulation tests do not seem helpful to assess the efficacy of plasma transfusion.
In conclusion, the appropriate dose has still to be defined, based on a clinically meaningful transfusion trigger.
Sonia Labarinas, Oliver Karam and Delphine Arni
Competing interests
I don't have any conflict of interest